Tool block

ABSTRACT

A tool block comprises plates providing therebetween a tool holder guide channel for preventing movement of a tool holder along two of three orthogonal axes while permitting slidable adjustment relative to a workpiece along the third or adjustment axis. A pair of preload blocks normally clamp the tool holder against movement along the adjustment axis. A pair of forked shaped wedges straddle the tool holder and are adjustably received in recesses cut in opposite sides of the tool holder. Each wedge has a set of ramp shaped cam surfaces inclined along the adjustment axis for cooperating with a set of mating ramp shaped cam follower surfaces on the tool holder recesses to overcome the clamping preload of the preload block and slide the tool holder in one direction along the adjustment axis.

United States Patent Douglas I 1 Nov. 27, 1973 TOOL BLOCK PrimaryExaminer-Leonidas Vlachos [75] Inventor: Henry Douglas, Saginaw, Mich.AtmmeyE' Chnsten et [73] Assignee: General Motors Corporation,

Detroit, Mich. [57] ABSTRACT A tool block comprises plates providingtherebetween [22] Filed May 1972 a tool holder guide channel forpreventing movement [21] Appl. No.: 257,884 of a tool holder along twoof three orthogonal axes while permitting slidable adjustment relativeto a workpiece along the third or adjustment axis. A pair [52] US. Cl82/36 R of preload blocks normally clamp the tool holder [51] Int. Cl.B23b 29/10 against movement alon the adhstment axis A air of 58] Fieldof Search 82/36 R 37 g 1 P l forked shaped wedges straddle the toolholder and are adjustably received in recesses cut in opposite sides of[56] References Clted the tool holder. Each wedge has a set of rampshaped UNITED STATES PATENTS cam surfaces inclined along the adjustmentaxis for 2,812,678 11/1957 Boley 82/36 cooperating with a set of matingramp shaped cam fol- 3,232,153 2/1966 Davis 82/36 lower surfaces on thetool holder recesses to over- 3,283,626 11/1966 Alvey et 82/36 come theclamping preload of the preload block and 2,475,049 7/1949 Fremo 82/36slide the tool holder in one direction along the adjustment axis.

TOOL BLOCK This invention relates to tool blocks and more particularlyto too] blocks for supporting and adjusting a tool holder relative to aworkpiece.

The present invention provides a tool block comprising base, side andcover plates providing a tool holder guide channel that prevents a toolholder from being moved along two of three mutually orthogonal axeswhile permitting slidable adjustment relative to a workpiece along athird or adjustment axis. A pair of preload blocks slidable on the toolholder bias it against the base plate so as to normally prevent movementalong the adjustment axis in the presence of cutting forces. The toolholder is straddled by a pair of forked shaped wedges that arethreadably engaged in the cover plate and are adjustably received inrecesses cut in the side plates and in opposite sides of the toolholder. Each wedge has a set of ramp shaped cam surfaces that cooperatewith a set of mating cam follower surfaces on the tool holder toovercome the preload on the tool holder and finely adjust it along theadjustment axis. One set of such ramp surfaces is inclined oppositely tothe other relative to the adjustment axis so that adjustment of onewedge in one direction transverse to the adjust mentaxis slides the toolholder in one axial direction relative to the workpiece and adjustmentof the other wedge in the same transverse direction slides the toolholder in the other axial direction. The preload blocks and wedgestherefore cooperate with the tool holder to permit axial adjustment ofthe tool holder without introducing backlash and without requiringloosening of the tool holder clampingstructures.

It is an object of the present invention to provide a new and improvedtool'block for supporting and adjusting a tool relative to a workpiece.

It is another object of the present invention to provide a tool block ofthe foregoing type wherein the tool holder may be finely adjusted alongat least one axis without first loosening any tool holder clampingdevices. 1

It is another object of the present invention to provide a tool blockwherein a preload device is provided to normally prevent a tool holderfrom sliding along an adjustment axis in the presence of cutting forcesand wherein a cam device is adjustable to engage the tool holder so asto overcome the preload thereon and slide the tool holder along theadjustment axis relative to the tool block and preload device.

It is another object of the present invention to provide a tool block ofthe foregoing type wherein the cam device includes a pair of cam membersspaced along an adjustment axis and adjustable to engage axially spacedcam follower sections cut on opposite sides of the tool holder,adjustment of one cam member finely adjusting the tool holder in oneaxial direction and adjustment of the other cam member finely adjustingthe tool holder inthe other axial direction.

It is a further object of the present invention to provide a tool blockwherein the tool holder is finely adjustable in either direction alongone axis without introducing backlash and without first looseningclamping devices.

These and other objects and advantages of the invention will become moreapparent with reference to the following description taken inconjunction with the accompanying drawings wherein:

FIG. 1 is a plan view of a tool block provided in accordance with thepresent invention;

FIG. 2 is a view taken along view 2-2 of FIG. 1;

FIG. 3 is a view taken along view 3-3 of FIG. 1;

FIG. 4 is a portion of a view taken along view 44 of FIG. 1;

FIG. 5 is a portion of a view taken along view 5-5 of FIG. 2;

FIG.; 6 is a perspective view of a portion of one element of the toolblock of FIG. ll;

FIG. 7 is a perspective view of another element of the tool block ofFIG. 1. With reference now to FIGS. 1 and 2, there is shown a tool block10 for supporting and positioning, as described in further detail below,a tool holder 12 holding a cutting tool 14 at a front end thereofrelative to a workpiece l6 suitably held and rotated by a machine 18 ona workpiece axis 19.

Tool block 10 is comprised of a support plate 20 bolted to machine 18 asshown and preload and cover plates 22 and 24 supported by a pair of sideplates 26 and 28 relative to a base plate 30 and bolted thereto asshown. Plates 22, 26, 28 and 30 provide a tool holder guide channel 32for guiding the adjustment of tool holder 12 ,along a longitudinaladjustment axis XX while also preventing movement of tool holder 12along mutually orthogonal transverse axes -YY and Z-Z orthogonal to theXX axis.

Tool block 10 is secured to machine 18 by four suitable bolts extendingthrough coarse adjustment holes insupport plate 20, two such bolts beingshown dotted and threadably engaged in a pair of holding blocks 42 and44 under base plate 30. To clamp base plate 30 against a support surface46 ground on support plate 20, four base plate clamping bolts 48 areprovided passing through coarse adjustment holes in base plate 30 andthreaded into support plate 20 so as to bias a pair of bolt plates 49against base surface 46.

A nut and screw arrangement 50 comprising a nut 52 and screw 54 areprovided to permit transverse adjustment of base plate 30 relative tosupport plate 20 when bolts 48 are loosened. Nut 52 is pinned by a pin56 to base plate 30, and screw 54 is journaled in a reaction bracket 58bolted to support plate 20 by two bolts 60. Reaction bracket 58 preventsaxial movement of screw 54 relative thereto by cooperation with a screwhead 62 and locking collar 64 pinned to screw 54 by pin 66. A key 68 issecured to support plate 20 by screws 70 (FIG. 3) and allows base plate30 to be slidably adjusted along transverse axis Y-Y on ground basesupport surface 46 when base plate adjustment screw 54 is turned into orout of nut 54 with bolts 48 loosened.

Preload plate 22 carrying cover plate 24 is supported by side plates 26and 28 which are positioned in a pair of longitudinally extendinggrooves 82 in base plate 30 and a pair of grooves 84 in preload plate22. Side plates 26 and 28 are locked against longitudinal movement inthese grooves by a pair of keys 86 extending along transverse axis Y-Y,and four studs 88 passing through holes in preload plate 22, cover plate24 and side plates 26 and 28 clamp these elements against base plate 30.

dicate movements thereof along the XX adjustment axis.

Tool holder 12 is preloaded in guide channel 32 between base surface 100ground on the top of base plate 30 and a pair of bronze preload blocks102 and 104 that are spaced axially along the XX adjustment axis andthat, as better seen in FIGS. 3 and 4, are slidably received on apreload block receiving surface 106 ground on the top of tool holder 12.A pair of preload screw 108 and 1 are piloted by counterbores 1 12 and114 in preload blocks 102 and 104 respectively and are threadablyreceived in cover plate 24. When screwed to urge preload blocks 102 and104 against top surface 106, screws 108 and 110 effect on tool holder 12a preload bias sufficient to prevent cutting forces on tool 14 whencutting workpiece 16 from sliding tool holder 12 along the XX axis onbase surface 100 in guide channel 32.

Two sets of guide grooves 120a and 120b and 122a and 122b, as best seenin FIG. 5, are cut respectively in side plates 26 and 28 alongtransverse axis ZZ for cooperating with tapered recesses 124 and 126, asbest seen in FIG. 6, cut on opposite sides of tool holder 12 to permitadjustment along the ZZ axis of a pair of fork shaped forward andrearward adjustment wedges 130 and 132, wedge 132 being best seen inFIG. 7. Extending through an opening 128 through preload plate 22,wedges 130 and 132 are selectively adjusted along the ZZ axis byrespective wedge adjustment screws 134 and 136 that are threadablyreceived in the wedges and in cover plate 24. As may be betterunderstood with reference to FIGS. 3, 4 and 5, forward adjustment wedge130 has a pair of legs 138a and 138k straddling tool holder 12 andhaving respective forwardly inclined ramp shaped cam surfaces 140a andl40b for cooperating when in a sliding camming engagement with a matingset of forwardly inclined cam follower surfaces 142a and l42b cut on thefront ends of tool holder tapered recesses 124 and 126 to force toolholder 12 forward along the XX axis. With surfaces 140 and 142 inclinedalong the XX axis from the bottom of tool holder 12 to the front topthereof as shown, downward adjustment of wedge 130 along the ZZ axisovercomes the preload applied by preload blocks 102 and 104 to toolholder 12 and slides tool holder 12 forward towards workpiece 16 inaccordance with thread pitch and rotation of adjustment screw 134.Similarly, rearward adjustment wedge 132, as better seen in FIG. 7, hasa set of legs 144a and 14411 with rearwardly inclined cam surfaces 146aand 1461; for cooperating when in a sliding camming engagement with amating set of rearwardly inclined ramp shaped cam follower surfaces 148aand l48b cut on the rear ends of tool holder tapered recess 124 and 126to force tool holder 12 rearwards along the XX axis. With surfaces 146and 148 inclined oppositely to surfaces 140 and 142, downward adjustmentof wedge 132 slides tool holder 12 rearwardly in a direction away fromworkpiece 16.

Side plates 26 and 28 together with base surface 100 therebetween thusprovide three sides of tool holder guide channel 32 and prevent movementof tool holder 12 when loaded therein along the XX and ZZ transverseaxes, and wedges 130 and 132 effect adjustment of tool holder 12 inguide channel 32 in opposite directions along the XX adjustment axis.Moreover, since they straddle tool holder 12, and force cam followersurfaces on opposite sides thereof, wedges 130 and 132 force tool holder12 along the XX axis while minimize torque couples tending to cock thetool holder in an XY plane in guide channel 32. And, by applying theforce along an axis in the body of tool holder 12 close to thelongitudinal axis thereof, torque couples tending to cock tool holder 12in an XZ plane are minimized. Since side plates 26 and 28 are thusclamped and locked against movement along the longitudinal XX axis andsince wedges 130 and 132 are locked against movement along the XX axisby the cooperation between wedge legs 138 and 144 and side plate groovesand 122, side plates 26 and 28 assure that the forward or rearwardsliding of tool holder 12 varies closely and repeatably with theadjustment of wedges and 132.

In normal operation, tool holder 12 is loaded into guide channel 32 oftool block 10 while preload plate 22 and cover plate 24 carryingtherewith wedges 130 and 132 extending through opening 128 are removed.Preload blocks 102 and 104 are next placed on tool holder top surface106 and are then covered by preload plate 22 and cover plate 24 so thatpreload adjustment screws 108 and 110 are loosely received in thecounterbo'res 112 and 114 of preload blocks 102 and 104. Cover platestuds 88 are next threaded into base plate 30 through preload plate 22and side plates 26 and 28 and are then tightened against cover plate 24.

Preload adjustment screws 108 and 110 are then tightened by the numberof turns necessary to bias tool holder 12 between base surface 100 andpreload blocks 102 and 104 with a preload bias suitable to preventsliding movement of tool holder 12 along adjustment axis XX in thepresence of contemplated cutting forces. While it has been found thatthe preload applied to too] holder 12 through preload blocks 102 and 104and surface 46 is normally sufficient to prevent movement of tool holder12 in the presence of normal cutting forces, it may be desirable toprovide additional assurance against such axial movement by loweringwedges 130 and 132 until the wedge cam surfaces and 146 justrespectively engage mating tool holder cam follower surfaces 142 and 148without moving too] holder 12.

Cutting tool 14 held by tool holder 12 is then coarsely adjusted alongthe XX adjustment axis with respect to workpiece by positioning thesupport plate 20 before the bolts 40 are tightened. Coarse positioningof tool 14 along the Y--Y direction with respect to the workpiece iseffected by suitable adjustment of nut and screw arrangement 50 beforebolts 48 are tightened. The fine adjustment of cutting tool 14 along theXX axis is then effected by appropriate adjustment of wedges 130 and 132along the Z-Z axis. To slide cutting tool 14 forwardly towards workpiece16 against the preload applied on tool holder 12, forward adjustmentwedge 130 is lowered by turning forward adjustment screw 134 either by anumber of turns known to provide the desired forward adjustment or untilthe desired forward adjustment is indicated on indicator 98. Whileeffecting such forward adjustment, rearward adjustment wedge 132 must beretracted upwardly so as to assure that cam surfaces 146 thereon are notin the path of travel of cam surfaces 148 cut on the sides of toolholder 12. Rearward adjustment of tool holder 12 is similarly effectedby raising forward adjustment wedge 130 out of the path of contemplatedtravel of tool holder 12 and lowering rearward adjustment wedge 132.

Having described one embodiment of the present invention, it isunderstood that the specific terms and examples are employed in adescriptive sense only and not for the purposes of limitation. Otherembodiments of the invention, modifications thereof and alternativesthereto may be used. I therefore aim in the appended claims to coversuch modifications and changes as fall within the true spirit and scopeof my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

It is claimed:

1. A tool block comprising:

a. a tool holder support having a tool holder guide channel extendingalong an adjustment axis for slidably guiding a tool holder along saidadjustment axis while preventing movement along a transverse axismutually orthogonal thereto;

b. a tool holder slidably received in said guide channel for holding acutting tool and finely adjusting the position thereof relative to aworkpiece, said tool holder having a recess in a side thereof forguiding cam means and having cam follower means in said recess forcooperating with said cam means to slidably and finely adjust said toolholder along said adjustment axis;

0. preload means slidably received on said tool holder for normallypreventing said tool holder from sliding along said adjustment axis bybiasing said tool holder against said tool holder support; and

d. cam means guided by said recess and transversely adjustable thereinalong said transverse axis for overcoming said bias provided by saidpreload means and sliding said tool holder along said adjustment axis onsaid tool holder support and said preload means by forcing said camfollower means along a forcing axis through said tool holdersubstantially parallel to said adjustment axis.

2. A tool block comprising:

a. tool holder support having a tool holder quide channel extendingalong an adjustment axis for slidably guiding a tool holder along saidadjustment axis while preventing movement along two transverse axesmutually orthogonal thereto;

b. a tool holder slidably received in said guide channel for holding acutting tool and finely adjusting the position thereof relative to aworkpiece, said tool holder having a recess in a side thereof forguiding cam means and having a pair of cam follower means in said recessfor cooperating with said cam means to adjust said tool holder alongsaid adjustment axis;

c. preload slidably received on said tool holder for normally preventingsaid tool holder from sliding along said adjustment axis by biasing saidtool holder against said tool holder support; and

d. a pair of cam means guided by said recess and transversely adjustabletherein along one of said transverse axes for overcoming said biasprovided by said preload means and sliding said tool holder means alongsaid adjustment axis on said tool holder support and preload means byforcing one of said cam follower means in one direction along saidadjustment axis when one of said cam means is adjusted and the other camfollower means in the other direction when the other cam means isadjusted.

3. A tool block comprising:

a. a tool holder support having a tool holder guide channel extendingalong an adjustment axis for slidably guiding a tool holder along saidadjustment axis while preventing movement along two transverse axesmutually orthogonal thereto, said tool holder support comprising a pairof spaced side plates for providing two side surfaces for said channel,each said side plate having cam grooves for guiding cam means;

b. a tool holder slidably received in said guide channel for holding acutting tool and finely adjusting the position thereof relative to aworkpiece, said tool holder having a pair of recess in opposite sidesthereof for cooperating with said side plate grooves to guide said cammeans, each said recess having a pair of ramp shaped cam followersurfaces oppositely inclined along said adjustment axis for cooperatingwith said cam means to adjust said tool holder along said adjustmentaxis;

c. preload means slidably received on said tool holder for normallypreventing said tool holder from sliding along said adjustment axis bybiasing said tool holder against said tool holder support; and

d. cam means comprising a pair of fork shaped wedges spaced axiallyalong said adjustment axis and transversely adjustable in said sideplate grooves and tool holder recesses along one of said transverse axesfor overcoming said bias of said preload means and forcing one of saidcam follower surfaces in one direction along said adjustment axis whenone of said wedges is adjusted and the other of said cam follower meansin the other direction when the other wedge is adjusted.

1. A tool block comprising: a. a tool holder support having a toolholder guide channel extending along an adjustment axis for slidablyguiding a tool holder along said adjustment axis while preventingmovement along a transverse axis mutually orthogonal thereto; b. a toolholder slidably received in said guide chanNel for holding a cuttingtool and finely adjusting the position thereof relative to a workpiece,said tool holder having a recess in a side thereof for guiding cam meansand having cam follower means in said recess for cooperating with saidcam means to slidably and finely adjust said tool holder along saidadjustment axis; c. preload means slidably received on said tool holderfor normally preventing said tool holder from sliding along saidadjustment axis by biasing said tool holder against said tool holdersupport; and d. cam means guided by said recess and transverselyadjustable therein along said transverse axis for overcoming said biasprovided by said preload means and sliding said tool holder along saidadjustment axis on said tool holder support and said preload means byforcing said cam follower means along a forcing axis through said toolholder substantially parallel to said adjustment axis.
 2. A tool blockcomprising: a. tool holder support having a tool holder quide channelextending along an adjustment axis for slidably guiding a tool holderalong said adjustment axis while preventing movement along twotransverse axes mutually orthogonal thereto; b. a tool holder slidablyreceived in said guide channel for holding a cutting tool and finelyadjusting the position thereof relative to a workpiece, said tool holderhaving a recess in a side thereof for guiding cam means and having apair of cam follower means in said recess for cooperating with said cammeans to adjust said tool holder along said adjustment axis; c. preloadslidably received on said tool holder for normally preventing said toolholder from sliding along said adjustment axis by biasing said toolholder against said tool holder support; and d. a pair of cam meansguided by said recess and transversely adjustable therein along one ofsaid transverse axes for overcoming said bias provided by said preloadmeans and sliding said tool holder means along said adjustment axis onsaid tool holder support and preload means by forcing one of said camfollower means in one direction along said adjustment axis when one ofsaid cam means is adjusted and the other cam follower means in the otherdirection when the other cam means is adjusted.
 3. A tool blockcomprising: a. a tool holder support having a tool holder guide channelextending along an adjustment axis for slidably guiding a tool holderalong said adjustment axis while preventing movement along twotransverse axes mutually orthogonal thereto, said tool holder supportcomprising a pair of spaced side plates for providing two side surfacesfor said channel, each said side plate having cam grooves for guidingcam means; b. a tool holder slidably received in said guide channel forholding a cutting tool and finely adjusting the position thereofrelative to a workpiece, said tool holder having a pair of recess inopposite sides thereof for cooperating with said side plate grooves toguide said cam means, each said recess having a pair of ramp shaped camfollower surfaces oppositely inclined along said adjustment axis forcooperating with said cam means to adjust said tool holder along saidadjustment axis; c. preload means slidably received on said tool holderfor normally preventing said tool holder from sliding along saidadjustment axis by biasing said tool holder against said tool holdersupport; and d. cam means comprising a pair of fork shaped wedges spacedaxially along said adjustment axis and transversely adjustable in saidside plate grooves and tool holder recesses along one of said transverseaxes for overcoming said bias of said preload means and forcing one ofsaid cam follower surfaces in one direction along said adjustment axiswhen one of said wedges is adjusted and the other of said cam followermeans in the other direction when the other wedge is adjusted.